Huguette Clark, left, with her sister, Andr�e.

Anna Clark with her daughters Huguette (left) and Andrée (center). Huguette holds one of her dolls.

With the new baby Huguette are Anna, W.A., and Andrée Clark in 1906.

Andr�e Clark with her little sister, Huguette.

Huguette Clark, left, with her sister, Andrée.

W.A. Clark with daughters Andrée, left, and Huguette at Columbia Gardens, his gift to the citizens of Butte, Montana, c. 1917.

W.A., Anna, Andrée (with her mother), and Huguette Clark (with her father), c. 1912.

The Clark girls were frequent transatlantic travelers, accustomed to the luxurious staterooms of the Cunard and White Star luxury liners. In 1911, newspapers across America carried a photo of Andrée, nearly nine years old, arm in arm with her niece of the same age, Katherine Morris, who was holding hands with Huguette, nearly five. They were standing on the deck of the RMS Adriatic, crossing the Atlantic to attend the coronation of George V, king of the United Kingdom.

Huguette, left, and Andr�e Clark, apparently with the Clark mansion in the background.

The sisters in Central Park with the Clark mansion tower in background.

Huguette Clark, left, with her sister, Andrée.

A music recital by children in the Clark Mansion on Fifth Avenue, New York.

W.A. and Anna Clark with their daughters, Andrée, left, and Huguette.

Signatures of sisters Andrée and Huguette Clark in the guest book of the Mowitza Lodge in Montana, owned by their half-brother Will Clark. Both list their residence as Paris, where they lived before moving to New York.

Huguette Clark, right, with her sister, Andrée, at the Mowitza Lodge in Montana, owned by their half-brother Will Clark, at left.

Huguette Clark, right, with her sister, Andrée, at the Mowitza Lodge in Montana, owned by their half-brother Will Clark.

Huguette Clark's sister, Andrée, at the Mowitza Lodge in Montana, owned by their half-brother Will Clark.

Anna Clark with her daughter, Andr�e. Anna, who went nearly deaf by middle age, had a variety of contraptions for enhancing sound.

Anna Clark with her daughter, Andr�e. Anna, who went nearly deaf by middle age, had a variety of contraptions for enhancing sound.

Andr�e Clark with her father, W.A.

Andrée Clark, Huguette's sister, c. 1917, the year of her death from meningitis.

After the death of 16-year-old daughter Andrée Clark from meningitis in 1919, W.A. Clark gives the deed to land for the first national Girl scout camp, Camp Andrée Clark, in New York. Huguette Clark, 13, stands with her father.

After the death of 16-year-old daughter Andrée Clark from meningitis in 1919, W.A. Clark gives the deed to land for the first national Girl Scout camp, Camp Andrée Clark, in New York. Huguette Clark, 13, stands with her father.

A painting of Andrée Clark, Huguette's sister, who died at 16. The painting is in Bellosguardo, the Clark summer home in Santa Barbara.

A painting of Andr�e Clark, Huguette's late sister, inside Bellosguardo, the Huguette Clark estate in Santa Barbara, California.

A painting of Andr�e Clark inside Bellosguardo, the Huguette Clark estate in Santa Barbara, California.

Andrée Clark, Huguette's sister, in a painting by Tadé Styka at Bellosguardo in Santa Barbara. She died before the family bought that house.

A painting of Andr�e Clark inside Bellosguardo, the Huguette Clark estate in Santa Barbara, California.

A painting of Andr�e Clark inside Bellosguardo, the Huguette Clark estate in Santa Barbara, California.

A painting of Andr�e Clark inside Bellosguardo, the Huguette Clark estate in Santa Barbara, California.

Andrée Clark, Huguette's sister, in a frame kept by Huguette.